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OEM Carrier Transformer 40VA 120V to 24V for C4850C50AY03561 — Ships Today
Carrier

OEM Carrier Transformer 40VA 120V to 24V for C4850C50AY03561 — Ships Today

SKU: CARRIE-C4850C50AY03561-TRANSFORMER-HT01BD236 Brand: Carrier

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Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

OEM Carrier 40VA Control Transformer HT01BD236 for Model C4850C50AY03561

This OEM step-down transformer (part number HT01BD236) is the factory-specified replacement for the Carrier C4850C50AY03561 packaged unit. The transformer steps down 120V line voltage to 24V AC to power the entire low-voltage control circuit — including the thermostat, contactor coil, gas valve, and control board. When this part fails, the system goes completely silent: the thermostat display may go blank, the contactor won't energize, and no heating or cooling operation is possible. If you've confirmed 120V supply at the unit but zero 24V output at the secondary terminals, this transformer is the likely culprit.

  • Specs: 40VA rating | Primary: 120V AC | Secondary: 24V AC | OEM part number HT01BD236 | Factory-matched output tolerance for stable control voltage
  • OEM vs Generic: OEM transformers are wound and insulated to exact factory specifications, ensuring consistent 24V output under load. Generic alternatives can sag under full control-circuit load, causing intermittent lockouts, nuisance trips, or premature control board failure.
  • Install difficulty: 2/5 — Disconnect all power before beginning. Tools needed: flathead and Phillips screwdrivers, multimeter, wire nuts or spade connectors. Label or photograph all low-voltage wiring before disconnecting. Verify 24V output at secondary after installation before restoring full power.
  • Warranty: 1-year OEM factory warranty against defects. In stock and ships same business day from our warehouse.

Compatibility: Engineered specifically for the Carrier C4850C50AY03561 packaged unit. Always verify your existing transformer's VA rating, primary voltage, and secondary voltage on the unit's data plate or wiring diagram before ordering. Need fitment confirmation? Our HVAC parts specialists are available to verify compatibility before you buy — order with confidence and get back up and running today.

Shipping Information

  • Orders placed before 3PM CST ship same business day
  • Standard delivery: 2-5 business days
  • Express shipping available at checkout
  • Free shipping on orders over $75
  • Tracking number emailed upon shipment

Return Policy

  • 30-day returns on unused parts in original packaging
  • Electrical parts (capacitors, contactors, control boards) are final sale once installed
  • Email info@nationalhvacparts.com to initiate a return
  • Refunds processed within 5-7 business days

Frequently Asked Questions

Does this Transformer fit my Carrier C4850C50AY03561 — Ships Today?
Yes. This is the factory-specified OEM transformer for the Carrier C4850C50AY03561 — Ships Today. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.
How do I replace the transformer on my Carrier C4850C50AY03561 — Ships Today?
Difficulty: Medium (30–45 min)
Step 1: Turn off breaker. Step 2: Photo wiring connections. Step 3: Disconnect wires from old transformer. Step 4: Remove mounting hardware. Step 5: Install new transformer, reconnect wires matching voltage ratings. Step 6: Verify 24V output with multimeter.
My thermostat has no power. What failed?
Thermostat with no display = failed 24V transformer (or blown control board fuse). Check the 3A/5A fuse on the control board first ($1–$5 fix). If fuse is good but no 24V output from transformer, replace transformer.
Is this transformer compatible with Bryant or Payne too?
Many Carrier parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.
Should I use OEM or aftermarket for my Carrier transformer?
OEM recommended for reliability and warranty compatibility. OEM parts match exact factory specifications for proper fit, performance, and safety. While aftermarket alternatives cost less upfront, the risk of improper fit and reduced lifespan usually makes OEM the better value long-term.
How fast does National HVAC Parts ship?
Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.
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Mike Rivera
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